1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_MESSAGE_LOOP_MESSAGE_LOOP_TASK_RUNNER_H_ 6 #define BASE_MESSAGE_LOOP_MESSAGE_LOOP_TASK_RUNNER_H_ 7 8 #include "base/base_export.h" 9 #include "base/callback.h" 10 #include "base/macros.h" 11 #include "base/memory/ref_counted.h" 12 #include "base/pending_task.h" 13 #include "base/single_thread_task_runner.h" 14 #include "base/synchronization/lock.h" 15 #include "base/threading/platform_thread.h" 16 17 namespace base { 18 namespace internal { 19 20 class IncomingTaskQueue; 21 22 // A stock implementation of SingleThreadTaskRunner that is created and managed 23 // by a MessageLoop. For now a MessageLoopTaskRunner can only be created as 24 // part of a MessageLoop. 25 class BASE_EXPORT MessageLoopTaskRunner : public SingleThreadTaskRunner { 26 public: 27 explicit MessageLoopTaskRunner( 28 scoped_refptr<IncomingTaskQueue> incoming_queue); 29 30 // Initialize this message loop task runner on the current thread. 31 void BindToCurrentThread(); 32 33 // SingleThreadTaskRunner implementation 34 bool PostDelayedTask(const Location& from_here, 35 OnceClosure task, 36 TimeDelta delay) override; 37 bool PostNonNestableDelayedTask(const Location& from_here, 38 OnceClosure task, 39 TimeDelta delay) override; 40 bool RunsTasksInCurrentSequence() const override; 41 42 private: 43 friend class RefCountedThreadSafe<MessageLoopTaskRunner>; 44 ~MessageLoopTaskRunner() override; 45 46 // The incoming queue receiving all posted tasks. 47 scoped_refptr<IncomingTaskQueue> incoming_queue_; 48 49 // ID of the thread |this| was created on. Could be accessed on multiple 50 // threads, protected by |valid_thread_id_lock_|. 51 PlatformThreadId valid_thread_id_; 52 mutable Lock valid_thread_id_lock_; 53 54 DISALLOW_COPY_AND_ASSIGN(MessageLoopTaskRunner); 55 }; 56 57 } // namespace internal 58 } // namespace base 59 60 #endif // BASE_MESSAGE_LOOP_MESSAGE_LOOP_TASK_RUNNER_H_ 61